19980005 has 6 divisors (see below), whose sum is σ = 23988006. Its totient is φ = 15976008.

The previous prime is 19979987. The next prime is 19980019. The reversal of 19980005 is 50008991.

It can be written as a sum of positive squares in only one way, i.e., 15984004 + 3996001 = 3998^2 + 1999^2 .

It is not a de Polignac number, because 19980005 - 2⁶ = 19979941 is a prime.

It is a super-4 number, since 4×19980005⁴ (a number of 30 digits) contains 4444 as substring.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 8996 + ... + 10994.

It is an arithmetic number, because the mean of its divisors is an integer number (3998001).

Almost surely, 2^19980005 is an apocalyptic number.

It is an amenable number.

19980005 is a deficient number, since it is larger than the sum of its proper divisors (4008001).

19980005 is an frugal number, since it uses more digits than its factorization.

19980005 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4003 (or 2004 counting only the distinct ones).

The product of its (nonzero) digits is 3240, while the sum is 32.

The square root of 19980005 is about 4469.8998870221. The cubic root of 19980005 is about 271.3512735305.

Adding to 19980005 its reverse (50008991), we get a palindrome (69988996).

The spelling of 19980005 in words is "nineteen million, nine hundred eighty thousand, five".